Automatic telegraph system



.4 1,541,316 E. P. NCROFT ET AL AUTOMATIC TELEGRAPH SYSTEM June 9, 1925.

Eff/3f June 9 1925.

E. P. BANCROFT ET AL A AUTOMATIC TELEG'RAPH SYSTEM Filed July 1, 1920 7 Sheets-Sheet I5y June 9, 1925.

1,541,35 a P. BANRoFT ET AL AUTOIATIC TELEGRAPH SYSTEM ,7 sheets-smet v EP. BANCROFT ET AL l AUTOHATIC TELEGRAPH SYSTEM FHM 1, 1920 June 1925.

Patented lune 9, 1925.

'TAS

ERWIN r. BANCROFT, or BnoonLYNQl/mn MARK B. KERK, or NEW YORK, N. Y., .as i

SIGNORS '.'LO WESTERN ELECTRIC COMPANY, INCORPORATED, 0F NEVI YORK,

N. Y.. A CORPORATION OF YORK.

AUTOMATIC TELEGRAPH SYS-TEM.

Application filed July 1,

T0 all 'whom t may concern.'

Be it known that we, EnwIN P. BnNoRorr and lllAnli-B. Kran, citizens of the United States, residing at Brooklyn, in the county of Kings and Stat-e otNew York, and at New York city, in the county or' New York and State ot New York, respectively, have invented certain new and useful 11nprove' ments in Automatic Telegraph `clysteins, ot' which the following is a tall, clear, concise, and exact description.

This` invention relates to automatic telegraph systems. An object o'l' the invention is to. provide a telegraph system which is flexible, one whereby an increased number of stations may he operatively included within the system, and one whereby any station connected therein may communicate directly and automatically with any other predetermined station. y i

Further objects of the invention are the provision of eicient and reliable means v:tor synchronizing, phase-finding and correcting for line lag. y

There are two principal or Well-known telegraph systems in general use, 'one the multiplex system, and the other the startstop system.

The multiplex printing telegraph system is particularly adapted for handling heavy` teh-graphie tratlie where printed messages are desired,- and is usually employed for communication over circuits ot' considerable length. ll'ith such a system, many messages may be transmitted over 'a line wire simultaneously, For example, a quadruple duplex system provides eight channels of communication. iour in each direction; and a ,sextuple duplex system provides twelve channelsl ot cominunieation, six in each direction. Current impulse distributors of the rotar \"t \'pe are employed and' vspecial apparatus is required for maintaining the dis tributors 1n synchronism.

In the past it has been extremely difticultto maintain more than two distributors in synehronism, but by means ot' recently developed electriral correcting systems it. is possible to maiir tain al large number of multiplex distributors in s vncln'onism with ordinaryv line conditions, and it is practicable to maintain in synchriinisinuoierl xferybad lines many more,

1920. Serial No. 393,393.

multiplex distributors than heretofore sible. The electrical method of correction,l

whereby this is possible, is Acovered by:

1,279,905 and ,United States Patents 1,292,048, and applications relating to i111A provements thereon. The start-stop system is one whereinlthe.

current impulse distributors make one c0111-,y

`\, where printed messages .are desired and is for vcommunication commonly 'employed over short lines and is sometimes termed a shortline system, although notlilmitedni'or' use over such lines as it is equally vsuitable for use over lines of great length. The system requires no synchronizing *apparatus-lin, 'asmuch as the distributors are autonfiatr cally restored to normal after each character isstransmitted. .f

This invention contemplates .various adaptations and combinations of the multipleX and start-stop systems and improves' ments therein whereby an unlimited n1unbe1:

' of stations may be placed. in direct commuf. nication with one another 1n an etiic1ent,'1n

The asso-` expensive and reliable manner. 'ciation broadly ot a multiplex and starte. stop system into a unitary structure where;v by niessage impulses Aare autoinaticall transferred trom one system to another and vice versa, is covered by Patent No. 1,407,042,f

issued F eb. 2l, 1922. This invention has tov do with improvements .on the systems dis-j closed in the above-mentioned copending application's and upon niultiplen aiulst-artf' stop systems in general, whereby' 'greatery flexibility and reliability vis attained iu the transmission of manv messages simultane-f ously over a limited number ofcircuits..

Referring to the drawings, Fig. 1 represents a typical Y-forlring arrangement vwith three terminal stations arranged for eom- ,munication with one another through a common or single repeating station; Fig, represents two terminal 'stations arranged for communication with one another through a repeating station with certain channels of each terminal station ter1ninat- 'ing at the repeatingl station. Fig'. 3 repre- -munication from each terminal multiplex trate in Fig. 2; rig.

station, through a repeating station, to each of the other terminal multiplex stations, and also illustrates-how one arm of the multiplex distributor at, say for example, St. Louis, may be extended by means of start-stop equipment to a distant or outlying station, and hour two arms of the multiplex. distributor at Chicago for example, may be extended by means of start-stop equipment to two outlying cities or stations. It is understood, of course, that any or all of the arms of each terminal multiplex station may be extended, if desired, to an. equal. number of distant or outlying stations by means o start-stop equipment. Fig. 5 illustrates diagrammatically the equipment and circuits required at the repeating station for handling eight channels of communication to and from each of three distant stations, as illustrated in Figs. 1 and 4; Fig. 6 illustrates diagrammatically the apparatus and circuits required ata repeating station with four channels repeating through and four channels of each of the terminal stations terminatin at the repeating station, as illus- 7 illustrates diagrammatically the apparatus and circuits required at a repeating station with one line arranged for quadruple duplex operation and each of two other lines arranged for double duplex operation, as illustrated in Fig. 3', Fig. 8 illustrates diagrammatically one of the multiplex terminal stations with three receiving channels terminating and 'three transmitting channels originating at the multiplex terminal station, with one transmitting and one receiving channel extended by means of start-stop equipment, as represented to the right of Fig. 9, to a distant or outlying station by means of startstop equipment, as illustrated to the left ot Fig. 9; and Fig. 10 represents a mechanical structure vfor shifting or orientating the brush arms of the multiplex distributor.

Referring, for the moment, to Figs. l, 2 and 3, the full lines indicate the number of channels of communication in one direction, and the broken or dotted lines, the number of channels of communication in the opposite direction. In each of these figures. the reference character O may be assumed to represent-operating tables or preferably a transmitting and receiving instrument located on ,the`- operating tables as is-customary -peating in actual practice. For the sake of illustration, the multiplex terminal stations in Figs. l and 3 are represented as indicating stations at New York, St. -liouis and Ghicago, respectively, with the repeating station located at Pittsburgh. ln Fig. 2 `the multiplea* terminal stations are indicated as representing stations at New York and Chicago, with the repeating station located at Pittsburgh. Fig. l represents a lull quadruple duplex system with two armsv of each multiplex terminal. station repeating through to each of the other multiplex termin-al stations. Fig. 2 represents a t'ull quadruple duplex system extending from each terminal station to the repeating station with two arms of each terminal station repeatin through to the other terminal station, an with two arms ol eacli.terininal station terminating at the repeating station. Fig. 3 represents a full quadruple duplex set extending from the New York terminal station to .the repeating station, With two double duplex sets extending from the repeating station to each of the other multipleit terminal stations. With reference to the systems shown diagrammatically in Figs. 1, 2 and 3, it is to be understood that the repeating station and all terminal multiplex stations connected thereto, operate in synchronism.

ln Fig. l there is shown diagranunatically a fullquadruple duplex system similar to Fig. l, with some of the multiplex arms ei;- tended by means of start-stop equipment to distant or outlying stations. At the New York terminal multiplex station there arc illustrated tour transmitters T and tour receivers R, arranged to be connected through the multiplex sending and receiving distributors Si.) and RD respectively, to the iilil.

line circuit LA extending to the repeating.

station at Pittsburgh. At the St. Louis terminal multiplex station there are illustrated three transmitting and three receiving instruments connected directly to the sending and receiving distributor faces with one quadrant of the receiving distributor connected to a start-stop sending distributor and one quadrant of the' transmitting distributor likewise connected to a start-stop receiving distributor for couumuiication over a line circuit to a distant or outlying station represented as Kansas City, which is provided also with transmitting and rcceiviug distributors of the start-stop type. At the Chicago terminal multiplex station there are shown two channels terminating and two originating in local apparatus. With the remaining four channels extended by means of start-stop equipment to distant or outlying stations, illustrated in the drawing as representing stations .at Gary and Milwaukee. At Pittsburgh, og lthe restation there are illustrated diameans et `a distributor brush 18.

-eeiving segments are illustrated asbeuig .of shorter length than the sending segments,

. faces SD, each comprise a continuous ring 13 and a segmented'ring 14. In the arrangement illustrated each ring 14 consists of twenty segments, each ot which is insulated from allottlie other segments and adapted to bev connected to its respective continuous ring 13 at regular recurring intervals, through a distributor brush 15. The receiving 'distributor RD likewise' comprises a continuous ring 16 and a seginented ring 17 comprising an equal number ot' insulated receiving segments. The receiving seg ments are also arranged to be connected rsequentially to the continuous ring 16, by

'lhe re- Whicli .is customaryr in actual practice, in

lorder that only tiie center or undistorted portion ,of 'each .signaling impulse will be received and distributed to the storing relays, 19 and 20. The storing relays 19 and 20 are each connected to alternate segments ofthe receiving distributor and each relay is adapted to receive and store alternate signals tor retransmission.

' Associated with each sending and receiving distributor repeater unit is a phasing key 9.1, liand 221 tor operating a plurality vot' contacts, and a lag-finding key Q2, 122 and 222 likewise adapted to control circuits through a plurality of contacts. lhe purpose of these keys will be described later. Frein reference to Fig. 5, it will be noted that the distributors, storing relays, switchingl means, etc. associated with each line cirvvcuit is a replica o 'that associated with veach of the other line circuits, consequently a description oi one-unit will suflice for all.

The 'phasing and lag-finding keys aS illusltratedin Fig. 5, are arranged tor repeating signals received over each line circuit out over 4je-acli'of the other line circuits.- For example, inthe arrange.; fut' ,.ioWn, selecting impulses received over the line circuit'l :LA will cause the operation of 'line relay it), and either positive battery 951er negative battery 2o will vbe connected through armature 2li ot' relay 10,5switgh .25, receiving dis- 4tributor ring 16, brush'lS, seginen'ts-l 1T, to,A storing relay 10 or 20 `depending upon the character ot the signaling impulse and the position otl brush 18 upon receipt of each signaling impulse. The relays 19 and 20 upon being energized, will actuate their :irinature 26 and ZT to connect positive or negative battery through the lower contacts of lag-tinding key 2Q, lower contacts ot the phase-finding keys 121 and Q21, associated with line 'circuits LB and LU, to the corresponding' sending` distributors and out over the line circuits LB and LC. ln order that the Vti'aitic ot signals troni each terminal station maybe properly repeated at the repeating station and distributed to the proper line circuits, it is necessary that the sending and receiving brushes at the terminal and repeating stations bear the proper phase'` relation with respect to one another, and` that the distributors at all stations operate in synchronisin. rlhis will be explained more in detail hereinafter. g

.ln connection with liigs, t5, Tand 8, there isshown a well-known phonic wheel motor 28 ot the LaCour type, driven by stationaryniagnets 29, arranged in pairs and each pair ot'iiiagncts is adaptedtii' be energized alternately over circuits controlled by av driving fork 30.,

In Fig. (i there is shown the necessary apparatus and circuit arrangements required at the repeating station for repeating two channels from each terminal station through to the other terminal station, with two arms :trom each terminal station terminating at the repeating station, as disclosed diagrammatically in F ig. 2. In Fig. 6, like Fig. 5, there is showin a pair of sending'distributor rings SD and a pair of receiving distributor rings RD associated with each line circuit. In addition to bthe regular sending and receiving rings, there is illustrated in connection with each distributor unit a pair of localrings, one of which is continuous, and the other segmented. 'llie local continuous ring 31 is shownfconnected to ground and the local segn'ients are adapted to be connected sequentially tothe grounded ring by 'means of a distributor brush 32, for controlling operations in the local receiving, and transmitting instruments. For example, the local distributor segmentsmay be utilized to control the operation of printing magnets in the receiving` printersand the operationA Ot' stepping or tape-feeding magnets oi antomatic tape transmitters. Referring to the sending distributors in F ig. 6, the first group' of live transmitting segments is connected directly to contacts of a local transmitter T,

and the AYthird lgroup ot' live sending seg-y ments is likewise connected to al local trans initter T, while the second and fourth groupsV of sending segments are arranged for the purpose et distributing impulses to the line circuit LA, which are received the line circuit LC., likewise the rstngroiip lot five noVv lill) receiving segments T he ieeeeiving discrihutot' RD is eomeeted to operating magnets of :i eeeiving device, such a. piiiitei. The hiid group of five receiving segmenis is iiewise coiziecied to a receiving' des/'icee whie the second omfh groups of re ceiviiig' segments zi'f'e ceiiieved *m soi'iig relays 1S) and 20, whereby the iiaipuises eeived mi those particular groupe of mens muy he goied und. ifeit'imsiiiitted through the second und fomh gienps of Segments of the sending iiit'rihum SS iis- Soeiaied -Wih the hue eii'ciait, i0 ih@ ohei eriiiinnl Station. The receiving i'mismittiig diSti-ihuing imi] iepeaiiigg unit associated with he line ei'eui L@ likewise adapied if) i'ansiui'. :mii receive ociiiiy *from eel-tain quadraiis uit' the diszrihuers, zuid io repeat through i0 the ether line section LA impulses i'eeeiiei on other predetermined qaehants.

n Fig. i is shown i'epening apparatus and circuits for s, system such as represented diagrmnmziieaiiy iii, Fiji. 3, and wherein veme quadrupie fhipiex eiieuit is f'ihed at ihe repeating sibaion inte um ouhie .dupiex circuits. In this zui'angeziieiit, he sending segments if the double disihutoi' faces we fwiee the ienggh of the Sending segnieiits the quadupie distributor face. iin the iur iangemen disclosed in Figs. ami G the emnpiee selections are reeeiveii 1mi Senf: out

from the qumhupie distiihutms; mi each @if the ioni' qmii'hfzins: whiie in Fig. coi plete seieeioiis :we ieeeifed amd sent out 'from the douhle distribuire): faces (hiring wich haii' revolution. 'in (ii-der te obtain the best working iesuis. 'fiom aV Sysex'ii of this kind, it is desiiahie to eiiipioy oui palm* iehiys for storing; anni @isti-ihuing the sigg :iis which crime iii over the quadruple eii3- enit 'and are@ he seni; out over une of the other of the two double Ciicuis. The tiaiic channels of the quadruple eiieuit :we ai* ranged so that the first chazineimhieh Eiei n'iaiy cui-responds to the Hfst qumiaiih @if the dismihutoi', uses the edil segments me the first ten segments; ihe second channel? even segments of the ,first ien, segmens; ti third @hannah the @dii segments if ih@ ser? and en segiiiens.; mici he .f'oiuh czimi'xei., the, even segiiie'nis mf theseeemi 'sen Segments. En this Way the qumhru'ige flistibw for husi.. iiivei he same distance per ehemne. :is che hizish mi the donhie isti'ihutm" and thereby eompeusfies for the difference iii iength of he dis'sihuimf segments.

The phasing; keys mid. higriiiuiihg Liege, diseieeed in Figs. G :und 7. mbe foi: he same pui-pase anni peimiii i'he saune unei'iens es; in the circuits Shewii in in this eoiiiieetien 'it muy he noee. tha

hy stnggeiiiig the adiaceu channels ofthe quadiupie circuit ou the @dei and even seg; meme of the distiihutmj betie? iiii'giiis we sei'iiieiit 4m,

obtained if ich@ fe'laigive pesiion of the hriieahes on the epeater dlsihiiwi is; Such *cors :we staggere with respee 'o each other;

that is, when. the qmdiiipie receiving brush. is on 35. #he subie sending brush for line LB she'i'ii he im ehe eifzef gait segment 44, and. the deuhieeniiig musifor hie LG should be, mi he ietei puri. ci?. with n eomes'gguieiiig ieiaiaiii of ihe reizeiviiig hi le: ci iiuhie sending hiuShesi 0i he quadiupie ciiiibum face werking in the ethe' iiectien.

The suecesu epeia'ieii ci' be. sysems diseosied iii im 'i' inclusive.) requires that the time lugs in. the seimmm Eines freni.' the repeuei saiitimi ie he Severini emlinai stations ere cei'npeiisaed :Em: sepeizieiy it the sending distiihiiors each of the i.e- Spective iei'miiiii mutipiez; miionsg Oher words, the seniing Frings me se?, 'hash (or the hi'ushes oiwai) ai; each of the' propel' insigni iem he severe?. :(iiiiizipiex that heh Ehe, sending and receiving 12h@ (oithe. brushes) may he menaei infie- Referring fof they mameii; sa Fig. 5, it wiii he neted hat ih@ aiimiuies. of -he Stm'- ing feiey's if and 2O ieiihiior-sending segizfiens are so mifamed imei @mme-stai that haii oi? 'the sigiziis i'eeeivei over iin@ LA me, reps aiefi im@ iin@ LE and haii: im@ LC, haii. of the sigmxis "ieeeii'eii from LB are repeaeci izio line LA. und haii iiige LQ. and iiiiiy, haii Si' he sigiiais iseceived from iine LC eeiite imo line 'LA and haii' iio line LE. The 'inaction of he higdmiing swieiiee i2?. und at the i'epeiitiiig; Sa'icm is 'effect *fe-sierung@- ment of h@ sending segmes m the dis tiibutcirs Wih' i'espee te he @wiring reims 19 and 2f). s iha @iii ef 'the signais Teeeiveid 'fieL-i line fi. me cepeae. hach i1-im hue L, siii imm ii'ie LB hacia im@ lime LB, :mei eli. frein iiie L@ bask im@ Eine LC.

ID A,

with repeating apparatus such, for exemple, as illustrrited iu Fig. 5., let it be assumed that the transmitter T and stertstop sending distributor 100, shown in Fig. 9, is located at lanses City, that the start-stop .iistributor 119 (Fig. 9) and multiplex sending distributor SD (Fig. 8) ere located St; Louis. llurther let it be assumed thet the. lsigneling; impulses sent out from the multiplier'. distributor SB (Fig. 8) are re.- ceivel 'et Pittsburgh over the line LB (Fig. )7 andv retrensmitted over the line LC to Chieftec, "which We assume is represeutedthy the multiplex receiving distributor RD il) where thel'signaling impulses are eotomaticelly transferred from the multi lex distributor RD to e. start-stop distributor 120 (Fig. 9) where the impulse ere retransmitted over o. Sturt-stop extension circuit to Gory, represented by e start-stop receiving distributor 11115 :md recorder R. At this point it is well 'to beur in mind that the multiplex distributors are continuously enel in synchronisni and that the Start-stop distributors at the distant stev tions ere controlled by the local contacts or segments on the terminal multiplex distribun tors. Let it be assumed that the character D which, according to the five unit code, is represented by live vunits of current, no current, no current, current, no `current, is to be transmitted. The stort-stop distributor 120 (Fig. 9) is controlled directly from u. local segment of the multiplex distributor (Fig. 8). Each time the local distributoi1 brush 66 passes over segment 65 en energiz ing circuit is completed through release magnet 68 from grounded battery 69, Windingr of magnet 68, segment G5, brush G6, ring o?, to ground, thereby causing magnet 68 to Withdraw pei/Wl Z6 'from engagement with the stort-stop distributor brush arno 75, whereupon the arm makes one complete revolution end is again arrested by 'the pewl 75. During each revolution of the startstop distributor erm 75, the brush 7? carried thereby completes e circuit from grounded battery @-0, continuous ment '28, through the changing relay til to ground. :nains energized While arm 75 is :it rest or while it is held by the 'howl '1"(3. fis soon, however, us the distribut-or erin 'I5 is released tributor brush 7T posses oil oi serment 75l, the circuit through the polechuugmg relay 8l. broken und its armature felis hau-l into engagement with its buck Contact, thereby connecting spacing current to the sturtstop extension circuit. By reason of the dupier; arrangement, the polar relays S25 und Si responsive only to in'xpulscs received over the start-stop extension circuit, heure relay 84: will respond to current controlled by relay armature 82 enf uponreceipt of .winding 'of poleleiey o1 reali. operatingy ring 79, brush "Z7, seg-2 the distriln'itor brush" and the dis,

messie spacing current, causes its armature 85 to open, the energizing circuit through release control relay 86. Relay 86, upon being deenergized, permits its armature 87 to fall back into engagement with its buck contact and complete circuits from grounded oettery 88, armature 87 and beck contact thereci', segment 89 o distributor 145, brush 90, segment 91, through release muguet 92 ot distributor 130 and release control relay 93 of distributor 100 in parallel. Release magnet 92, When energized, withdraws the VVpewl 94 und releases brush erm 95 of distributor 145; and relay 93, when energized, completes un energizing circuit through release megnet 96 of the sending start-stop distributor 190. Relay 93, when energized, also completes e teni orar holding circuit for itself, which is bro en s ortly after the distributor brush erm 97 is released. Now' assuming that the combination representing the char- :roter D has been set up on Athe transmitter 'il (Fig. 9), contacts 101 und 104 will be closed und the remaining contacts will be o cned. 'While the distributor brush arm 9 isnt rest, a. circuit is established through pole-changing relay 108, from groundedv butn tery 196, distributor ring 107, distributor brush 98, segment 99, through the winding or' relay 198, to ground. Now, the instant the distributor erm 97 is released, brush 98 passes oli` of segment 99, the circuit through relay 108 is broken and its armature 109 tells back into engagement with its back contact, thereby connecting spacing current to the start-stop extension circuit and causfing line relay 83 to actuate its armature and 'open the energizing circuit of release control relay 111. Relay 111, upon being deenergized, permits its armature to fall beck into engagement with. its bock Contact, thereby completing e. circuit from grounded bat-' tery 112, armature of relay 111, 0beck contuct thereof, segment 113 of distributor 119, brush 11e, grnent 115, through the winding of release magnet 116, to ground. The completion of this circuit causes magnet 116 to withdraw the pawl 117 from engagement with the distributor brush arm 118.

released and tree to rotate due to frictional `engzigenfient between the brush arm Iand e segment' 1.50, contacts 101 of transmitter T,

The distributor brush arms 97 and 118 are now naciera through the winding of pole-changing relay 108, to ground, thereby placing,I marking current on the start-stop extension circuit and causing the operation of relay 111 through the operation ot' line relay 815. The brush 114: ot distributor 110 will make engagement with distributor segment 135 the instant relay 111 responds to the iirst niark- 'ing impulse of the signaling group, thereby con'ipleting a circuitfroin grounded battery 112, armature ofi-clay 111 and iont contact f brush 150 and continuous ring ot' distrilurtor SD. ln like manner, when distributor brush 98 ot' distributor 100 engages segment,

Asent over the start-stop extension circuit to vcause the operation ot signal-storing relu)Y 73 in the same manner as relay 70, and a connection will be established from niarking battery,armature 144 of'rclay 73, to the fourth segment oit the iirst quadrant of the sending distributor Si). rllhe armature 109 of relay 108 will engage its back contact `multiplesY distributorbrnsh 1511 (Fig. 8)

passes over the tirst and iourth segments ot y u 1 u vthe first quadrant ot sending, distributon SD, marking impulses will be sent to' line I while 'the distributor brush Siti-passes overy and received through the line relay 11 (lilith,

5). These impulses will operate relay 1l and cause its armature to moveiutoengaec- "meut with grounded battery 151, thcrcby 'connecting marking battery to the continuous ring 152 oil the receiving distributor RD. rlhe instant the tirst impulse is connected to riug15-2, the distributor brush 15S-i makes engagement with the iirst segment of 'the first quadrant, namely, segment 154k, thereby cmnpleting a circuit from grounded battery 151, arniature of relay 11, ring 152 brush 153, segment lflf, through the winding 'of storing relay 19 to ,ground .Relay 19, upon being ope 1ated, by current from battery 151 completes a circuit trom marking battery,

through armature 2G, contacts 155 ofY lagfinding key 122, contacts 156 of phasing key 221, sending segment 15T of the sending dis trihutor associated withl line ,circuit LC.

The distributor brush 158, in passing overy mitteryv segment 15T connects -inarking through the continuous distributor ring," 152), to the apesY of the polar relay 12, and over the line circuit LC. Since the second, third and litth impulses representing the character l) are spacingcurrent, the storing polar relays 19 and 20 will be actuated t0 connect spacingr current to the, sending segments of distributor 50 associated with line circuit LC whenthe receiving distributor brush 15S passes over segments 16th 161y land ltinsso'.L elated with line circuit LB.k Howeveigsince the fourth impulse is a marking" impulse, the brush liiny passing over receiring distributor segment-162, will cause storing re lay 2t) to be actuated to connect, marking battery. to the corresponding segment of send4 ing distributor Sl) associated with line circuit LC. This icuit will be established 'from rnarlrirugv battery, armature. 27, storing relay 20, contacts 161 of lag-Ending key 122,. contacts 165 of phasing key 221, segment 166 otV distributor SD. brush 158, ring 159 to liuc circuit LG.v rihus it will be seen that the repeating apparatus shown in Fig. 5 serves to receive impulses over any one of4 a plurality o't line circuits, store or rejuvenate the line impulses, and retransmitftheV signals over another of a plurality of line circuits.

lt- 'has been assumed that the impulses sent out from the repeating' station (Figef) over4 the-line LC would be receiied throughthe line relay 167 (Fig. 8). Relay ltf. controls, through its arma-ture 168 and contacts thereof, relays 16S) and 170.. Relay 169 responds to the actuation of relay'l and is arranged, upon receipt of marking impuls-es, to connect battery 171 through armature 172 of relay 169, to the receivingcontinuous ring 173 of distributor RD. New, if We assume that relays 16?" and 169 will, in response to mariting line impulses, connect battery 171 to segments 174 and 177 ot distributor RD, as the brush 175 passes over these segments, energizing circuits will be completedl through storing; relays G0 and 63 associated with start-stop distriluitor l120. through the contacts ot switching' key Storing relays lto 711, inclusive.

' ot relays 60 andwlj and front contacts therelili? which is segmented. The segments ot the segmented ringI are adapted to be connected to the continuous ring 203, by means of' a rotating brash 511Go. Bearing in mind that the speed. oi? the distributors at the terminal multiplex station shown in Fig. 8 is controlled by or corrected 'from the repeating or pace-setting station, and assuming that the distributor brushes travel slightly faster than the distributor brushes at the pace-setting station, then :it is necessary to slowdown or dampen the speed of the terminal distributors automatically and at rapidly recurring intervals. This is accomplished by varying the resistance in circuit of the operating magnet 195, through the instrumentality of relays 170, 201 and the correcting distributor. It Will be noted that relay 170 is operated from grounded battery 20G, controlled oy-,the armature 168 of line relay 1G?. 1Whenever the line relay armature 168 maires engagement with one or the other of its contacts, current -`vvill flow from grounded battery i206, armature 168, through one yWinding of relay 170 to ground,

and consequently armature 181 will be moved into engagement "with one or the other of its contacts. New the length of time current flows through either Windin ot' rela 201 will be determined by the position o distributor brush 205, and the interval of time between the making or' a contact, by relay armature 168, and the breaking of a Contact, by relay armature 181. That is, if We assume that the brush 205 is traveling slightly ahead of the distributor at the pace-setting station and that if when this occurs a reversal of line current is received, then current will ow from grounded battery Q06, armature 16S, through one vinding oi" relay 170 to ground, and also over another path through the corresponding Contact ot' relay 170, armature 181 correcting ring 203, brush 205, segment 2G-l, and through Winding of relay 201 lto ground, thereby operating relay 201 and causing it to move its arn'iatui'e 200 into engagen'ient with cont: ct 199 thereby shortcircuiting the resista-hoes 19T, and consequently reducing the speed of the driving magnet- 192. rlhis method of speed-correcting or synchronizing is more fully described in Patent #12H/1,905, issued September 2li, 1915.

At each of the terminal multiler stations and each ot the repeating stations there is provided ordinary hilorse signaling keysl @1 0 and Sounders 211. These instruments are adapted to be connected Vto the line by means oi 'switches or keys for Morse signaling purposes.v Y In Fig. 10 there is shown stationary multiplex distributor face 215, a rotcable brush arm 216, and a motor 21? for drivingP the rotatable member. @n the motor shaft 218 is mounted a ily-Wheel 219 of a Well known type. The distributor brush is driven by means of bevelled gears 219 and 220 cooperating with a. bevelled gear. 224! keyed to the motor shaft 218. The gear 220 is carried by a normally lined or stationary member 29.5. The mein ber 225 is provided with a handle or exten sion whereby the distributor bri 216 may be advanced or retarded any amount desired while the distributor brush arm 216 is being driven by the motor 21?. This fea# ture isv very desirable for bringing the dis! tributors into synehronisin or into the de sired phase relation and is disciosed more fully and claimed in a copen A application, Serial No. 420,908 tiled ovember 1, 1920.

While the preferred embodiments of this invention are disclosed in 'the accompanying drawings, it will be readily understood that various and niunerous changes may be made in the circuits and arrangements 'of the apparatus without departing from the spirit of the invention. lll/Thilo only a. limited number of possib conibiuations have. been illustrated, it conten'iplated that various and many other combinations may be used, in :tact it is contemplated. that in addition to the Y-.torlring arrangement as illustrated infFigs. 1, 8 and 4;, New York, for example, instead ot' acting as a terminal station, may be equipped with repeating; apparatus similztr to the Pittsburgh station., with certain of the arms from the if'eiv York repeating station extended to a terminal station, for example-'Wasl'iingtoin with other arms extended to another terminal station, ttor example Boston. lilith such an arrangement, several channels of communication. may be provided between lvashing ton and St. Louis, and Chicago, by 'way of the repeating stations at New York and Pittsburgh, While other channels may be provided between Boston and St.' Louis and Chicago by way of repeating stations at New York and Pittsburgh.

Another combination contemplated is the employment oi. a system somewhat similar to .those represented in Figs. 1 and except that a triple duplex arrangement may be provi led between New York and Pittsburgh, with tivo o3?. the arms extended to Si Louisv and one to Chicago, and in addition thereto one arm extending from Louis to Chicago by Way of Pittsburgh with another arm connecting Chicago and Pittsburgh. Thus it will. be seen that by reason oi the improved methods of synchronizing, phaseg finding and lagtinding.v the system is reudered extremely flexible and may be readily vadapted to meet various traltlc conditions. it should also be noted that by reason of lOU the special synchronizing arrangement, if-

auy line, extendingnfrom a terminal station to a repeating station, should be broken. or

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apparatus, means whereby each of said stations may communicate with a predetermined one of the other stations, and a plurality of storing relays at the repeating station associated with each line circuit and circuit connections eeetive so that said relays are invariably operated alternately for repeating the line signals from one station to another.

11. In a telegraph system, a plurality of terminal multiplex. stations, a repeating station, continuously operated distributing apparatus at each of said stations, means for .sending a predetermined combination of signaling impulses from one of said termina] stations to said repeating station, means at said repeatigstation for causing the retransmission of a corresponding group of impulses back to said terminal station, mechanism at said terminal stations oomprising a series of signaling devices for indieating the line lag, and means thereat for compensating for such `line lag. s

Inf-witness whereof, I hereunto subscribe my name this 26th day of June A. D., 1920.

ERWIN P. BANCRO'FT. MARK B. KEER. 

